A DESCRIPTION OF SMS - A COMPUTER CODE FOR SHIP MOTION SIMULATION

This report is a theoretical description of the time domain ship motion simulation program SMS. The program incorporates three basic mathematical models for ship motions; i) plane motion in calm water, ii) wave induced ship motions, and iii) ship motions in waves including manoeuvring. In the two latter models, radiation and diffraction forces are based on the linear strip approach, while Froude-Krylov forces are exactly computed at each time step by integrating the undisturbed pressure over the momentarily submerged hull surface. In irregular waves, radiation and diffraction forces in the time domain are obtained by the use of convolution integrals. Some examples are provided to demonstrate the application of the program to different non-linear problems of ship dynamics.